20474-49-1Relevant academic research and scientific papers
Direct Synthesis of Mono-α-arylated Ketones from Alcohols and Olefins via Ni-Catalyzed Oxidative Cross-Coupling
Yang, Peng-Fei,Shu, Wei
supporting information, p. 6203 - 6208 (2020/08/12)
Controlled synthesis of α-monoarylated ketones is significant yet challenging due to the site-selectivity issues and nonproductive overarylation reactions. Herein, we reported the direct synthesis of α-arylated ketones enabled by Ni-catalyzed dehydrogenative cross-coupling reaction cascade between alcohols and olefins. The use of readily available and cost-effective alcohols and olefins provides a straightforward access to monoarylated ketones in good yields with exclusive selectivity without using any advanced synthetic intermediates.
One-Pot Conversion of Allylic Alcohols to α-Methyl Ketones via Iron-Catalyzed Isomerization-Methylation
Latham, Daniel E.,Polidano, Kurt,Williams, Jonathan M. J.,Morrill, Louis C.
supporting information, p. 7914 - 7918 (2019/10/16)
A one-pot iron-catalyzed conversion of allylic alcohols to α-methyl ketones has been developed. This isomerization-methylation strategy utilized a (cyclopentadienone)iron(0) carbonyl complex as precatalyst and methanol as the C1 source. A diverse range of allylic alcohols undergoes isomerization-methylation to form α-methyl ketones in good isolated yields (up to 84% isolated yield).
C -Methylation of Alcohols, Ketones, and Indoles with Methanol Using Heterogeneous Platinum Catalysts
Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Jamil, Md. A. R.,Toyao, Takashi,Shimizu, Ken-Ichi
, p. 3091 - 3103 (2018/04/14)
A versatile, selective, and recyclable heterogeneous catalytic method for the methylation of C-H bonds in alcohols, ketones, and indoles with methanol under oxidant-free conditions using a Pt-loaded carbon (Pt/C) catalyst in the presence of NaOH is reported. This catalytic system is effective for various methylation reactions: (1) the β-methylation of primary alcohols, including aryl, aliphatic, and heterocyclic alcohols, (2) the α-methylation of ketones, and (3) the selective C3-methylation of indoles. The reactions are driven by a borrowing-hydrogen mechanism. The reaction begins with the dehydrogenation of the alcohol(s) to afford aldehydes, which subsequently undergo a condensation reaction with the nucleophile (aldehyde, ketone, or indole), followed by hydrogenation of the condensation product by Pt-H species to yield the desired product. In all of the methylation reactions explored in this study, the Pt/C catalyst exhibits a significantly higher turnover number than other previously reported homogeneous catalytic systems. Moreover, it is demonstrated that the high catalytic activity of Pt can be rationalized in terms of the adsorption energy of hydrogen on the metal surface, as revealed by density functional theory calculations on different metal surfaces.
Regioselective 1,2-Diol Rearrangement by Controlling the Loading of BF3·Et2O and Its Application to the Synthesis of Related Nor-Sesquiterene- and Sesquiterene-Type Marine Natural Products
Wang, Jun-Li,Li, Hui-Jing,Wang, Hong-Shuang,Wu, Yan-Chao
supporting information, p. 3811 - 3814 (2017/07/26)
The regiocontrolled rearrangement of 1,2-diols has been achieved by controlling the loading of BF3·Et2O. Its applicability is showcased by the divergent synthesis of austrodoral, austrodoric acid, and 8-epi-11-nordriman-9-one, as well as a formal synthesis of siphonodictyal B and liphagal. A new light is shed on piancol-type rearrangements that will be useful in diversity-oriented synthesis of related natural products.
Nickel-Catalyzed Hydroacylation of Styrenes with Simple Aldehydes: Reaction Development and Mechanistic Insights
Xiao, Li-Jun,Fu, Xiao-Ning,Zhou, Min-Jie,Xie, Jian-Hua,Wang, Li-Xin,Xu, Xiu-Fang,Zhou, Qi-Lin
supporting information, p. 2957 - 2960 (2016/03/19)
The first nickel-catalyzed intermolecular hydroacylation reaction of alkenes with simple aldehydes has been developed. This reaction offers a new approach to the selective preparation of branched ketones in high yields (up to 99%) and branched selectivities (up to 99:1). Experimental data provide evidence for reversible formation of acyl-nickel-alkyl intermediate, and DFT calculations show that the aldehyde C-H bond transfer to a coordinated alkene without oxidative addition is involved. The origin of the reactivity and regioselectivity of this reaction was also investigated computationally, which are consistent with experimental observations.
C-C coupling of ketones with methanol catalyzed by a N-heterocyclic carbene-phosphine iridium complex
Quan, Xu,Kerdphon, Sutthichat,Andersson, Pher G.
supporting information, p. 3576 - 3579 (2015/03/04)
An N-heterocyclic carbene-phosphine iridium complex system was found to be a very efficient catalyst for the methylation of ketone via a hydrogen transfer reaction. Mild conditions together with low catalyst loading (1 mol%) were used for a tandem process which involves the dehydrogenation of methanol, C=C bond formation with a ketone, and hydrogenation of the new generated double bond by iridium hydride to give the alkylated product. Using this iridium catalyst system, a number of branched ketones were synthesized with good to excellent conversions and yields.
Iridium-catalyzed selective α-methylation of ketones with methanol
Ogawa, Shinji,Obora, Yasushi
supporting information, p. 2491 - 2493 (2014/03/21)
Iridium-catalyzed selective α-dimethylation and α-methylation of ketones or phenylacetonitriles, using methanol as the methylating agent, were achieved. In addition, three-component cross α-methyl-alkylation was successfully performed using methyl ketones with methanol and primary alcohols with long-chain alkyl groups. This method provides a very convenient direct route to α-methylated ketones, using methanol.
Stereoselectivity in the Condensation Reactions of 1-Phenylethyl Alkyl and Phenyl Ketones with Organometallic Reagents
Alvarez-Ibarra, Carlos,Arjona, Odon,Perez-Ossorio, Rafael,Perez-Rubalcaba, Alfredo,Quiroga, Maria L.,Santesmases, Maria J.
, p. 1645 - 1648 (2007/10/02)
Stereochemical results of the condensation reactions of a series of ketones, PhCHMeCOR (R= Me, Et, Pri, But, Ph), with various organomagnesium and organolithium derivatives in ethers as solvents are reported.Results are accounted for on the basis of competition between two transition states which may adopt either Karabatsos- or Felkin-type conformations according to the nature of R, the reagent nucleophilicity, and the polarity of solvent.Polar and steric analysis of this reaction allows highly stereoselective syntheses of diastereoisomeric α-phenylalkanols to be devised.
Dianions Derived from α-Halo Acids. The Darzens Condensation Revisited
Johnson, Carl R.,Bade, Thomas R.
, p. 1205 - 1212 (2007/10/02)
The dianions of α-halo carboxylic acids are readily generated by the addition of the acids to 2 equiv of lithium diisopropylamide at low temperatures.When the mixture warms to room temperature dimeric products are formed.When aldehydes and ketones were added to the cooled solutions of the dianions and the reaction mixtures were allowed to warm to room temperature, followed by acid quench, glycidic acids were formed.The glycidic acids, per se, were often too unstable to be isolated and purified but could be analyzed by conversion to their methyl esters withdiazomethane.When the reactions were quenched prematurely, α-chloro-β-hydroxy carboxylic acids were isolated.Homologated aldehydes and ketones were obtained from the glycidic acids by catalytic and thermal decarboxylation methods.
